1. Technical Field
The present disclosure relates to the technical field of onboard batteries that are installed in vehicles, such as automobiles, and can be used even in cold areas.
2. Related Art
Onboard batteries are installed in various vehicles, such as automobiles, in order to supply electric power to motors and other various electrical components.
In recent years, in particular, vehicles such as electric vehicles (EV), hybrid electric vehicles (HEV), and plug-in hybrid electric vehicles (PHEV) have gained widespread use. In these electricity-driven vehicles, onboard batteries having a high electricity-storage function are installed.
An onboard battery includes a housing case and a battery module housed in the housing case. The battery module is configured by, for example, arranging a plurality of battery cells (secondary batteries), such as nickel hydrogen batteries or lithium ion batteries. In an onboard battery to be installed in an electric vehicle or the like, in order to retain a high electricity-storage function, a plurality of battery modules are disposed in the housing case and battery cells in each of the battery modules are connected in series or in parallel.
An example of an onboard battery is a type in which the plurality of battery modules are disposed in the housing case as a structure for retaining a high electricity-storage function (see Japanese Patent No. 5206110).
In such an onboard battery, inside the housing case are disposed, in addition to the plurality of battery modules, various devices including a control device that controls these battery modules and an auxiliary device for charging in a non-running state of the vehicle, such as nighttime.
As described above, the onboard battery has, in addition to the plurality of battery modules, various devices including the control device and the auxiliary device disposed therein, and thus, the internal temperature of the housing case may be easily increased by heat generated when the battery modules or devices are driven.
Therefore, in order to secure normal operation of the battery modules or devices, the increase in the internal temperature of the housing case needs to be suppressed. The above-described onboard battery, in which the plurality of battery modules are disposed, generates an especially large amount of heat. Therefore, it is desirable to increase a cooling performance of cooling the components disposed inside the housing case.